Pulpstone



Apgil 27, 1937. T, LARSSON 2,078,451

PULPS TONE Filed Dec. 6, 1935 'atentec pr. 27, 193'? UNITED STATES 1 l .T.E11\IT OFFICE 2,078,451 ,A n 1?ULrscrtuSrn`` .1 Thure Larsson, Worcester', Y assigr'ior VLt'o Norton Company, Wdrcestei`Mass., a', corporation of Massachusetts Application December 6,1935, Serial No. 53,228

2 Claims.

The invention relates to segmental grinding wheels and with regard to its more specific features to artificial pulpstones for the grinding of logs into pulp for paper manufacture and the like.

One object of the invention is to provide a pulpstone assembly which can be readily tightened after its manufacture. Another object of the invention is to provide an adjustable built-up pulpstone construction including a concrete center. Another object of the invention is to provide a pulpstone construction in which the parts, after assembly and tightening are securely locked in place. Other objects will be in part obvious or in part pointed out hereinafter.

The invention accordingly consists in the features of construction, combination of elements, and arrangements of parts, as will be exemplified in the structure hereinafter to be described and the scope of the application of which will be indicated in the following claims.

In the accompanying drawing in which is shown t one of various possible embodiments of the mechanical features of this invention,

Figure 1 is a fragmentary elevation of a portion of a pulpstone constructed. in accordance with the invention;

Figure 2 is a transverse sectional view taken on the line 2-2 of Figure 1;

Figure 3 is an elevation of a bolt;

Figure 4 is a. perspective view of a nut;

Figure 5 is a perspective view of a wedge block;

Figure 6 is an elevation of a wrench.

The invention may be embodied in a pulpstone of the general type disclosed in the United States patent to Larsson and Beth No. 1,736,161, granted November 19, 1929. I provide a number of abrasive segments I 0 which may be of the general type indicated in the aforesaid Letters Patent, and are preferably composed of abrasive grains bonded by means of vitried ceramic material. I provide a concrete center II which is in the form of a cylindrical drum with a relatively thick wall. This concrete center may be made in any suitable manner so far as the present invention is concerned, and it may be reinforced with annularly formed steel piping or the like. Embedded in the concrete center or drum II are a plurality of L-bolts I2. These bolts I2 are located in the radial axial planes which lie between adjacent abrasive segments I0, and a plurality of bolts are located between each pair of segments.

The bolts I2, as better shown in Figure 3, may be made of rod steel or iron stock bent over at one end I3 and being threaded at the other end I4. I provide a plurality of nuts I5, as showii in Figure 4, which have internal square sockets I6 to receive an end wrench and are internally threaded at the other end Il, The nuts I5 preferably have cylindrical outer surfaces of two diameters separated by a shoulder I8.

Referring now to Fig. 2, I provide a plurality of wedge blocks 20 each of which is approximately as long as the radial axial divisions between successive segments I0. Each wedge block has a number of holes 2| equal to the number of bolts I2 and these holes 2l have counterbores 22 to receive the shoulders I8 of the nuts I5.

As shown in Fig. 1, divisions between adjacent segments I0 are enlarged at 23 to form bores located in line With the axes of the nuts I5 and of the bolts I2. By means of wrenches 25 having, as shown in Fig. 6, square ends 26, the nuts I5 may be turned after the segments have been located on the center II.

The wedge blocks are located in cut-out portions between segments I0 which cut-out portions have inclined shoulders 3| to receive the thrust of the wedge blocks. In assembling, the bolts I 2 are embedded in the concrete I I and project therefrom. The wedge blocks 20 are placed in position between each pair of segments as the segments are moved into position, and in each wedge block are located the required number of nuts I5. Without turning the nuts I5 the segments I0 can be moved inwardly to contact the concrete center I I, or any thrust receiving material inserted between the segments I0 and the center II. The cut-out portions 30 are large enough to allow the nuts I5 to move outwardly under such conditions. When it is desired to secure the segments I0 in place, however, the wrenches 25 are inserted in the enlargements 23 and the nuts are thereby turned, tightening the wedge blocks 20 against the shoulders 3| or any interposed material 32. The cracks 33 between segments may then be lled with any desired filler, for example with Babbitt metal. Thereafter if it is desired to tighten the segments the Babbitt or other material can be drilled out of the enlargements 23.

It will thus be seen that there has been provided by this invention an apparatus in which the various objects hereinabove set forth together with many thoroughly practical advantages are successfully achieved. As Various possible embodiments might be made of the mechanical features of the above invention and as the art herein described might be varied in various parts, all without departing from the scope of the invention, it is to be understood that all matter hereinbefore set forth o-r shown in the accompanying drawing is to be interpreted as illustrative and not in a limiting sense.

I claim:-

1. A pulpstone comprising, an integral center portion, segmental abrasive blocks spaced around said center portion and shaped to form a cylindrical peripheral surface, wedge blocks located in 10 cut-out portions of the segmental abrasive blocks said wedge blocks being located in the planes of the cracks between the segmental abrasive blocks, bolts imbedded in the center portion, rotatable nuts received in the wedge blocks and positioned 15 to cooperate with the bolts, there being enlarge- THURE LARSSON. 

